I guess the solution really comes down to what is causing GreenDog's back pain. Is it muscular or spinal/vertebrae issues?
I had a slightly sore back before in high-school, but it never really bugged me that bad because most of the sports I did like running track and soccer kept the back fairly upright so that the muscles only had to just balance the upper-body's weight over the spin & hips.
However, when I went to university and got into cycling and bike-racing, this really brought the weak back-muscles into the forefront. In cycling, you're bent over and the upper-body's weight has to be supported by the back-muscles. In addition, the push from the legs tends to push the body upwards, which then needs to be counteracted by pulling on the handlebars and transmitting that force through the back. Needless to say, within a couple weeks after starting cycling, I was laid out in bed and on painkillers.
Recommendations from the doc was to get lots of bed-rest and stay away from activities that pulled my back. Well...this was really just relieving the symptoms and not solving the actual problems:
weak back-muscles that can't deal with the loads I was imposing on them.
Luckily, we had a sports-center with chiropractors and PTs experienced with cycling injuries. They had me gradually work on flexibility and strength. Lots of stretching and pilates to loosen up the muscles & back during the recovery. Then they had me gently work the lower back muscles in the gym. Simple back-lifts in the roman-chair built up the muscles. After a month, I could get around again without a cane. Then we started on building up strength by hanging onto weights while doing the back-lifts. Eventually I could lift a 50lb weight on the roman-chair.
Getting back on the bike after 3-months of recovery and strenght-building was a transformation. I could do 3-4 hour rides now whereas my limit before was just 90-minutes before back-pain made me stop. I could do all-out 100% sprints at speed without worrying about pulling out my back. I ended up having 10 great years of bike-racing and made it to the Olympic Trials in '92 in Washington.
So... rather than just "feel-good" relieving of the symptoms that just forces you to "make do" with your weaknesses, my suggestion is to find the actual problem that causes the pain and work on that,